If you are new to LIDAR you can find background information on this
web page. The local LIDAR coverage is far
from complete, nevertheless it is still a marvellous resource. This page contains links to view
the local LIDAR images that are available as indicated on the 10sq km grid
map below. The resolution is generally at 1 metre per pixel
although in a few smaller areas 50cm or 25cm per
pixel is occasionally available, however the downloads on this page are all at 1m as it has the
most extensive
coverage. The format chosen does not show woodland or buildings. If you
are interested in the technical aspects of this data including mapping
survey data then have a look
at this page.

LIDAR images can be
illuminated by a 'virtual sun' from any direction of the compass and at
varying elevations. Two downloads have been made available
with the 'virtual sun' at 210° and 300° from north (azimuth), and at 40°
in elevation. Therefore the two images show shadows cast at 90° from one another. As image
definition is crucial and each map covers 10km x 10km, the
file sizes can be up to 43MB each
depending on the LIDAR coverage within the tile. The next images illustrate what LIDAR
looks like. The grid chosen is NY64 located west of Alston.

NY64 is shown
left. As you can see the available image is only approximately
half of the 10km x 10km grid, and then within that half perhaps
only 40% has LIDAR data.

The
red X at the
top right of the image is the location of Whitley Castle (Roman
Fort), which is shown in detail in the two images below.

This
indicates how you need to zoom into LIDAR images and then pan around
them to reveal the detail. You can zoom in further still, but as
these are raster images they will eventually begin to pixelate.

These two
images have been illuminated by a 'virtual sun' from 300° (left image) and 210° (right image).

You
can see how the appearance of individual features varies.

Downloads:

A zip file for
each 10km x 10km grid can be downloaded.

Each zip file contains:

a) A README.txt
file regarding conditions of use and an explanation of the six digit
British National Grid co-ordinates used etc.,

b) The two LIDAR images
at 210° and 300° .

c) A grid image file
that shows the LIDAR against the British National Grid.

d) An OpenStreetView Map
image of that grid to aid orientation.

e) Some zip files
contain the coverage map right. It can also be downloaded by
clicking it.

View the images in your image
viewer; where you should be able to zoom and pan around each image. In many
image viewers the zoom control is the + and - keys (or mouse wheel
control) and panning is achieved by holding a left click on the image and dragging, or by use of the
keyboard arrow keys.

If you use this data in any form
of publication or lecture then please acknowledge:
altogetherarchaeology.org

Image processing:
Each OS grid is 10km square or 10,000m x 10,000m. The tiff
image produced using QGIS is 10,000 x 10,000 pixels hence
the 1m resolution where 1 pixel represents 1 square metre.
The tiff image is converted to a jpg file type using
zero compression to maximise sensitivity.
The jpg image size is the same as the tiff at 10,000 x
10,000 pixels. The jpg images has had a gamma correction
factor of 0.6 applied to improve contrast.